The present invention relates to an internal combustion engine, and more particularly, to an apparatus for selectively deactivating one or more cylinders of an internal combustion engine.
Generally, in an internal combustion engine, fuel is burned in a combustion chamber, and the internal combustion engine is operated using power that is generated when the burned fuel expands. An internal combustion engine is provided with a plurality of cylinders. Deactivation of one or more cylinders during low engine load and allowing the remaining cylinders to carry the load increases fuel economy. Such multi-cylinder engines capable of cylinder deactivation have been produced. Typically, in the case of an in-line 4 cylinder engine, two cylinders are deactivated; in the case of a V-6, three cylinders (one bank) are deactivated. Here, xe2x80x9cdeactivating a cylinderxe2x80x9d means inhibiting any of intake of an air/fuel mixture, combustion, and exhaust of combustion gas, while allowing reciprocating motion of a piston.
Typically, the deactivation of cylinders is performed by an apparatus for disabling the camshaft such that the intake valve is maintained in a closed state. However, cylinder deactivation apparatus according to the prior art require an apparatus for disabling the camshaft, and therefore, manufacturing costs increase.
In a preferred embodiment of the present invention, an apparatus for deactivating one or more cylinders of an internal combustion engine comprises a surge tank, an air distributor, and an intake manifold. The surge tank inclues a plurality of chambers that temporarily store air provided from a throttle body. The air distributor selectively provides air to the chambers of the surge tank. The intake manifold is connected to the chambers of the surge tank. Preferably, the surge tank is divided into two chambers by a dividing wall, and the air distributor is disposed between the throttle body and the surge tank.
In a further preferred embodiment, the air distributor comprises a first plate, a second plate, a rotator, and a plurality of air distributing tubes, wherein the first plate is provided with a plurality of openings equidistantly located on a circular line formed at a constant radius from a center thereof. The second plate is rotatably disposed proximate to said first plate, the second plate being provided with a plurality of openings located at positions corresponding to the openings of the first plate and one additional opening located on the circular line midway between any two of the equidistantly located openings. The rotator rotates the second plate, and the plurality of air distributing tubes provide communication between the openings of the first plate and the chambers of the surge tank.
More preferably, the rotator comprises a rotating rod, a connecting rod, and an actuator. One end portion of the rotating rod is connected to the second plate; the connecting rod is hingedly connected to the other end portion of the rotating rod; and the actuator moves the connecting rod such that the rotating rod rotates. It is preferable that the actuator is a solenoid.
It is further preferable that the first plate is provided with two openings, and that the second plate is provided with two openings corresponding to the openings of the first plate and one additional opening located midway between the two openings on the circular line formed at a constant radius from the center thereof.
In a further alternative embodiment of the invention, a housing communicates with an air intake. An air distributing member is disposed in the housing. At least first and second distributing tubes communicate with the housing and with a surge tank. The surge tank is divided into first and second chambers, each chamber communicating with one of the tubes. Each chamber communicates via an intake manifold with a selected number of cylinders less than all cylinders of the engine. Preferably, the air distributing member comprises first and second plates. The first plate defines at least first and second openings, each opening being aligned with one of the distributing tubes. The second plate is disposed between the first plate and the distributing tubes and is rotatable between a first position permitting air flow to all distributing tubes and a second position blocking air flow to at least one distributing tube.
In a further preferred embodiment, the second plate defines a first set of two openings alignable with the first and second distributing tubes and a second set of one opening rotatably displaced from the first set and alignable with one distributing tube. The apparatus may also comprise a rotating rod secured to the second plate, a connecting rod cooperating with the rotating rod, a connection bar pivotably connected to the connecting rod, and a solenoid acting on the connection bar. Actuation of the solenoid rotates the second plate to a predetermined orientation.